docs: def get_sdf(identifier, namespace='cid', domain='compound',operation=None, searchtype=None, **kwargs):
      """Request wrapper that automatically parses SDF response and supresses NotFoundError."""
      try:
          return get(identifier, namespace, domain, operation, 'SDF', searchtype, **kwargs).decode()
      except NotFoundError as e:
          log.info(e)
          return None